| Message ID | 1459258007-24968-1-git-send-email-bigeasy@linutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Le 29/03/2016 15:26, Sebastian Andrzej Siewior a écrit : > Currently the driver will disable the clock and enable it one line later > if it is switching from periodic mode into one shot. > This can be avoided and causes a needless warning on -RT. > > Tested-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> > Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Absolutely makes sense: Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Thanks. > --- > drivers/clocksource/tcb_clksrc.c | 33 +++++++++++++++++++++++++++++---- > 1 file changed, 29 insertions(+), 4 deletions(-) > > diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c > index 4da2af9694a2..ed1ae4445e8d 100644 > --- a/drivers/clocksource/tcb_clksrc.c > +++ b/drivers/clocksource/tcb_clksrc.c > @@ -74,6 +74,7 @@ static struct clocksource clksrc = { > struct tc_clkevt_device { > struct clock_event_device clkevt; > struct clk *clk; > + bool clk_enabled; > void __iomem *regs; > }; > > @@ -91,6 +92,24 @@ static struct tc_clkevt_device *to_tc_clkevt(struct clock_event_device *clkevt) > */ > static u32 timer_clock; > > +static void tc_clk_disable(struct clock_event_device *d) > +{ > + struct tc_clkevt_device *tcd = to_tc_clkevt(d); > + > + clk_disable(tcd->clk); > + tcd->clk_enabled = false; > +} > + > +static void tc_clk_enable(struct clock_event_device *d) > +{ > + struct tc_clkevt_device *tcd = to_tc_clkevt(d); > + > + if (tcd->clk_enabled) > + return; > + clk_enable(tcd->clk); > + tcd->clk_enabled = true; > +} > + > static int tc_shutdown(struct clock_event_device *d) > { > struct tc_clkevt_device *tcd = to_tc_clkevt(d); > @@ -98,8 +117,14 @@ static int tc_shutdown(struct clock_event_device *d) > > __raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR)); > __raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR)); > + return 0; > +} > + > +static int tc_shutdown_clk_off(struct clock_event_device *d) > +{ > + tc_shutdown(d); > if (!clockevent_state_detached(d)) > - clk_disable(tcd->clk); > + tc_clk_disable(d); > > return 0; > } > @@ -112,7 +137,7 @@ static int tc_set_oneshot(struct clock_event_device *d) > if (clockevent_state_oneshot(d) || clockevent_state_periodic(d)) > tc_shutdown(d); > > - clk_enable(tcd->clk); > + tc_clk_enable(d); > > /* slow clock, count up to RC, then irq and stop */ > __raw_writel(timer_clock | ATMEL_TC_CPCSTOP | ATMEL_TC_WAVE | > @@ -134,7 +159,7 @@ static int tc_set_periodic(struct clock_event_device *d) > /* By not making the gentime core emulate periodic mode on top > * of oneshot, we get lower overhead and improved accuracy. > */ > - clk_enable(tcd->clk); > + tc_clk_enable(d); > > /* slow clock, count up to RC, then irq and restart */ > __raw_writel(timer_clock | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO, > @@ -168,7 +193,7 @@ static struct tc_clkevt_device clkevt = { > /* Should be lower than at91rm9200's system timer */ > .rating = 125, > .set_next_event = tc_next_event, > - .set_state_shutdown = tc_shutdown, > + .set_state_shutdown = tc_shutdown_clk_off, > .set_state_periodic = tc_set_periodic, > .set_state_oneshot = tc_set_oneshot, > }, >
On 03/29/2016 03:26 PM, Sebastian Andrzej Siewior wrote: > Currently the driver will disable the clock and enable it one line later > if it is switching from periodic mode into one shot. > This can be avoided and causes a needless warning on -RT. I don't see the connection between the description and the content of the patch. It can be avoided by not disabling the clock when going to periodic / oneshot. The function below suggest clk_enable() is called twice, is that the real issue ? > Tested-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> > Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > --- > drivers/clocksource/tcb_clksrc.c | 33 +++++++++++++++++++++++++++++---- > 1 file changed, 29 insertions(+), 4 deletions(-) > > diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c > index 4da2af9694a2..ed1ae4445e8d 100644 > --- a/drivers/clocksource/tcb_clksrc.c > +++ b/drivers/clocksource/tcb_clksrc.c > @@ -74,6 +74,7 @@ static struct clocksource clksrc = { > struct tc_clkevt_device { > struct clock_event_device clkevt; > struct clk *clk; > + bool clk_enabled; > void __iomem *regs; > }; > > @@ -91,6 +92,24 @@ static struct tc_clkevt_device *to_tc_clkevt(struct clock_event_device *clkevt) > */ > static u32 timer_clock; > > +static void tc_clk_disable(struct clock_event_device *d) > +{ > + struct tc_clkevt_device *tcd = to_tc_clkevt(d); > + > + clk_disable(tcd->clk); > + tcd->clk_enabled = false; > +} > + > +static void tc_clk_enable(struct clock_event_device *d) > +{ > + struct tc_clkevt_device *tcd = to_tc_clkevt(d); > + > + if (tcd->clk_enabled) > + return; > + clk_enable(tcd->clk); > + tcd->clk_enabled = true; > +} This function.
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c index 4da2af9694a2..ed1ae4445e8d 100644 --- a/drivers/clocksource/tcb_clksrc.c +++ b/drivers/clocksource/tcb_clksrc.c @@ -74,6 +74,7 @@ static struct clocksource clksrc = { struct tc_clkevt_device { struct clock_event_device clkevt; struct clk *clk; + bool clk_enabled; void __iomem *regs; }; @@ -91,6 +92,24 @@ static struct tc_clkevt_device *to_tc_clkevt(struct clock_event_device *clkevt) */ static u32 timer_clock; +static void tc_clk_disable(struct clock_event_device *d) +{ + struct tc_clkevt_device *tcd = to_tc_clkevt(d); + + clk_disable(tcd->clk); + tcd->clk_enabled = false; +} + +static void tc_clk_enable(struct clock_event_device *d) +{ + struct tc_clkevt_device *tcd = to_tc_clkevt(d); + + if (tcd->clk_enabled) + return; + clk_enable(tcd->clk); + tcd->clk_enabled = true; +} + static int tc_shutdown(struct clock_event_device *d) { struct tc_clkevt_device *tcd = to_tc_clkevt(d); @@ -98,8 +117,14 @@ static int tc_shutdown(struct clock_event_device *d) __raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR)); __raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR)); + return 0; +} + +static int tc_shutdown_clk_off(struct clock_event_device *d) +{ + tc_shutdown(d); if (!clockevent_state_detached(d)) - clk_disable(tcd->clk); + tc_clk_disable(d); return 0; } @@ -112,7 +137,7 @@ static int tc_set_oneshot(struct clock_event_device *d) if (clockevent_state_oneshot(d) || clockevent_state_periodic(d)) tc_shutdown(d); - clk_enable(tcd->clk); + tc_clk_enable(d); /* slow clock, count up to RC, then irq and stop */ __raw_writel(timer_clock | ATMEL_TC_CPCSTOP | ATMEL_TC_WAVE | @@ -134,7 +159,7 @@ static int tc_set_periodic(struct clock_event_device *d) /* By not making the gentime core emulate periodic mode on top * of oneshot, we get lower overhead and improved accuracy. */ - clk_enable(tcd->clk); + tc_clk_enable(d); /* slow clock, count up to RC, then irq and restart */ __raw_writel(timer_clock | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO, @@ -168,7 +193,7 @@ static struct tc_clkevt_device clkevt = { /* Should be lower than at91rm9200's system timer */ .rating = 125, .set_next_event = tc_next_event, - .set_state_shutdown = tc_shutdown, + .set_state_shutdown = tc_shutdown_clk_off, .set_state_periodic = tc_set_periodic, .set_state_oneshot = tc_set_oneshot, },